This invention relates to an apparatus for loading cargo containers and flat racks off of the bed of a truck and onto a trailer using a hook lift system located on the truck.
Containers are used extensively to ship cargo by ship, rail and truck and a container can be transported on all three modes in a single trip. At large loading facilities the containers are loaded onto and off of the ships, railcars or trucks with large cranes. However, it often is desirable to load or unload a container from a truck at a smaller facility that does not have a crane. In order to accomplish this the trucks are equipped with a hook lift system that clamps to the front of the container. The hook lift system uses a series of levers and hydraulic cylinders to raise the front end of the container, which rotates the container about a rotary slide located at the rear of the truck that carries the container. The hook lift system then pushes the container rearwardly until its lower edge rests on the ground, as shown in FIG. 21. The weight of the container then causes the truck to roll forward until it is free of the container. The hook lift system then sets the front end of the container on the ground. The hook lift system loads the container from the ground onto a truck in essentially the reverse manner.
Flat racks are used to carry a load that is to be placed in a container when it is desired to remove the load from the container but not disassemble it. At times these flat racks are transported outside of the container and they can be loaded onto and off of a truck using the hook lift system on the truck.
The hook lift system is also used to load a container or flat rack onto a trailer. To accomplish this the container or flat rack is first loaded onto the truck and then unloaded from the truck onto the trailer. The problem with this is that unless the bed of the trailer is perfectly lined up longitudinally with the bed of the truck, the container or flat rack will not be centered on the trailer or will be cocked relative to the center line of the trailer. In addition, the rear end of the container or flat rack must be slid across the entire length of the trailer with metal to metal contact.
The subject invention provides an apparatus for using the hook lift system for unloading a container or flat rack from a truck and placing it on a trailer, and vice versa, without having to slide the lower rear edge of the container across the entire trailer bed. The apparatus also ensures that the container or flat rack is centered squarely on the trailer. A carriage, having a cradle which is configured to releasably receive a cross member located at the lower rear edge of a container, travels along the entire longitudinal extent of the trailer on a track system located on the trailer. The carriage also has a receptacle which releasably receives wheels which are located at the rear of some flat racks. A support stand located on the carriage releasably receives the rear edge of a flat rack that does not have wheels. In one preferred embodiment of the invention there are guides which center the container on the cradle as its rear end is being loaded onto the cradle. In another preferred embodiment there are releasable locks which secure the front and rear of the container to the trailer.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.